I've been trying to think about how this might work. and it raises a lot of questions.
I assume the factory had one (or maybe 2 or three) connections to the power network, metered by SAPN and billed by a power retailer. Behind the meter are a few solar panels and diesel generator(s) owned by Holden.
Now everything behind the meter will become a microgrid, with the addition of a battery and maybe some more solar panels. And instead of there being one customer behind the meter (GMH) the plant will be subdivided and each tenant will need to be separately provisioned and metered.
There are three components to the grid in Australia:
Power Generators
Distribution Networks
Power Retailers
So who will be responsible for these three functions in the Holden site Microgrid? Hopefully EMC will do all of them - almost certainly it will do the generation and distribution.
Also, will EMC take over the existing diesel generator(s)? - certainly make sense, and in conjunction with the battery will protect the site from outside catastrophic events like the "Big Blackout".
How will the microgrid interface to the main grid? Will it look like a large retail customer who might generate a little excess power from time to time and send it back to the grid at miniscule feed-in tariff rates, or will it also become a fully-fledged power generator that can sell power to the SA grid at current market rates? Hopefully the latter, as this will give them a lot of flexibility to arbitrage energy prices for the benefit of themselves and their customers, for example by selling power from the battery into the grid at times of high power use such as the evening peak when many of the tenants in the plant will have gone home for the day anyway.
There is a lot of potential here, and if done well, hopefully will become a model for future microgrids in Australia with applicability to both urban and non-urban situations.
